1. Field of the Invention
The present invention relates to a distillation apparatus and a distillation method.
2. Description of the Related Art
Conventionally, various kinds of distillation apparatus have been provided for separating, through distillation, a plurality of components contained in a material liquid in order to obtain predetermined components as products.
For example, in the case of a material liquid containing three components A, B, and C, in which component A is lower in boiling point than component B, and component B is lower in boiling point than component C; i.e., component A is a low-boiling-point component, component B is a medium-boiling-point component, and component C is a high-boiling-point component, the following distillation apparatus is used to separate components A to C of the material liquid through distillation.
FIG. 1 conceptually shows a conventional distillation apparatus.
In FIG. 1, reference numeral 201 denotes a first distillation column; reference numeral 202 denotes a second distillation column; reference numerals 203 and 205 denote evaporators; and reference numerals 204 and 206 denote condensers. The first distillation column 201 includes, from top to bottom, a first section 211, a second section 212, a third section 213, a fourth section 214, and a fifth section 215. An unillustrated packing element is disposed in each of the second section 212 and the fourth section 214, to thereby form an enriching section in the second section 212 and an exhaust section in the fourth section 214. The second distillation column 202 includes, from top to bottom, a first section 216, a second section 217, a third section 218, a fourth section 219, and a fifth section 220. An unillustrated packing element is disposed in each of the second section 217 and the fourth section 219, to thereby form an enriching section in the second section 217 and an exhaust section in the fourth section 219.
For example, when a material liquid M containing three components A, B, and C is fed into the third section 213 of the first distillation column 201, vapor rich in component A is discharged from the top of the first distillation column 201 and sent to the condenser 204, there the vapor is condensed into liquid rich in component A. The liquid rich in component A is discharged as distillate from the condenser 204. A portion of the distillate is refluxed as a refluxed liquid into the first distillation column 201, whereas the remaining distillate is discharged to an external destination.
Liquid rich in components B and C is discharged as a column-bottom liquid from the bottom of the first distillation column 201. A portion of the column-bottom liquid is sent to the evaporator 203, where the column-bottom liquid is evaporated through application of heat to become vapor rich in components B and C. The vapor rich in components B and C is returned to the first distillation column 201. The remaining column-bottom liquid is fed into the third section 218 of the second distillation column 202.
When the column-bottom liquid is fed into the third section 218, vapor rich in component B is discharged form the top of the second distillation column 202 and sent to the condenser 206, where the vapor is condensed into liquid rich in component B. The liquid rich in component B is discharged as distillate from the condenser 206. A portion of the distillate is refluxed into the second distillation column 202, whereas the remaining distillate is discharged to an external destination.
Liquid rich in component C is discharged as a column-bottom liquid from the bottom of the second distillation column 202. A portion of the column-bottom liquid is sent to the evaporator 205, where the column-bottom liquid is evaporated through application of heat to become vapor rich in component C. The vapor rich in component C is returned to the second distillation column 202. The remaining column-bottom liquid is discharged to an external destination.
Next will be described a distillation apparatus to be applied to the case where components B and C are high-melting-point materials.
FIG. 2 conceptually shows a conventional distillation apparatus to be applied to the case where a medium-boiling-point component and a high-boiling-point component are formed from respective high-melting-point materials.
In FIG. 2, symbol M denotes a material liquid containing three components A to C; reference numeral 201 denotes a first distillation column; reference numeral 202 denotes a second distillation column; reference numerals 203 and 205 denote evaporators; and reference numerals 204 and 206 denote condensers.
When the condenser 206 employs ordinary cooling water as cooling medium for cooling vapor rich in component B discharged from the top of the second distillation column 202, and the melting point of component B is higher than the temperature of cooling water (for example, the melting point of component B is higher than a cooling water temperature of 30xc2x0 C. to 35xc2x0 C.), vapor rich in component B cannot be condensed before the temperature of the vapor rises sufficiently high after operation of the distillation apparatus is started. During that period of time, the vapor solidifies within the condenser 206; thus, liquid rich in component B cannot be obtained as distillate.
In order to prevent the above-mentioned solidification of the vapor rich in component B within the condenser 206, a cooling system 225 connected to the condenser 206 uses a cooling medium heated to a temperature higher than the melting point of component B, such as hot water, cooling oil, or steam, until a predetermined period of time elapses after the operation of the distillation apparatus is started. Distillate is discharged from the condenser 206 to a line L11; a portion of the distillate is refluxed into the second distillation column 202 through a line L12; and the remaining distillate is discharged through a line L13. In order to prevent solidification of the distillate within the lines L11, L12, and L13, the lines L11 to L13 assume a double-pipe structure.
Liquid rich in component C, which serves as a column-bottom liquid, is discharged from the bottom of the second distillation column 202 to a line L15; a portion of the column-bottom liquid is sent to the evaporator 205 through a line L16; and the remaining column-bottom liquid is discharged through a line L17. In order to prevent solidification of the column-bottom liquid within the lines L15 to L17 when the temperature of component C is higher than ambient temperature, the lines L15 to L17 assume a double-pipe structure. The double-pipe structure includes an inner pipe and an outer pipe disposed concentrically. Steam serving as a heating medium is caused to flow through the space between the inner and outer pipes to thereby prevent solidification of the distillate or the column-bottom liquid flowing through the inner pipe.
In order to reduce energy consumed for heating the column-bottom liquids in the evaporators 203 and 205, preferably the evaporators 203 and 205 are lowered in temperature. However, when the evaporators 203 and 205 are lowered in temperature, evaporation of the column-bottom liquids becomes difficult accordingly. In order to cope with this problem, vacuum generators 227 and 228 are connected to the condensers 204 and 206, respectively, so as to establish a negative pressure within the first and second distillation columns 201 and 202. As a result, the column-bottom liquids can be readily evaporated. Also, vent gas generated within the first and second distillation columns 201 and 202 can be drawn out and released into the atmosphere.
However, when the condenser 206 and the vacuum generator 228 are directly connected, a portion of vapor rich in component B is mixed with the vent gas and sent from the condenser 206 to the vacuum generator 228. The vapor solidifies within the vacuum generator 228, breaking the vacuum generator 228. In order to cope with this problem, a vent gas treatment apparatus 230 is disposed between the condenser 206 and the vacuum generator 228 so as to remove the vapor rich in component B from the vent gas. The vent gas treatment apparatus 230 includes condensers 231 and 232 for separating the vent gas and the vapor from each other. Lines L21 to L23 for connecting the condenser 206 and the condensers 231 and 232, lines L24 to L26 for connecting the condensers 231 and 232 and the vacuum generator 228, and lines L27 to L29 for draining the condensers 231 and 232 assume a steam trace pipe structure.
However, employment of the above-mentioned auxiliary apparatus causes an increase in area occupied by the distillation apparatus and an increase in cost.
FIG. 3 is a view for explaining a conventional cooling system. Structural features similar to those in FIG. 2 are denoted by common reference numerals, and repeated description thereof is omitted.
Vapor rich in component B discharged from the second distillation column 202 is sent, through a line L31, to the condenser 206, where the vapor is condensed and discharged as a distillate to a line L11. In order to prevent solidification of the vapor within the condenser 206, hot water heated to a temperature higher than the melting point of component B is fed as a cooling medium to the condenser 206.
The cooling system 225 includes a hot water tank 235, a cooler 236, a pump 237, and valves 238 and 239. Before operation of the distillation apparatus is started, the valve 238 is opened so as to feed cooling water to the hot water tank 235 through an unillustrated line and a line L32 such that the hot water tank 235 stores cooling water by a volume required to start up the cooling system 225; ice., by a hold up volume. For a predetermined period of time after operation of the distillation apparatus is started, the valve 238 is held open to feed steam to the hot water tank 235 through the line L32.
Water contained in the hot water tank 235 is heated to a temperature higher than the melting point of component B by means of the steam. Thus-obtained hot water is sent to the cooler 236 via a line L36, the pump 237, and a line L35. The cooler 236 cools hot water to a predetermined temperature higher than the melting point of component B by means of low-temperature water. Thus-temperature-regulated hot water is fed to the condenser 206 through a line L34 and causes vapor rich in component B to be condensed within the condenser 206. In this manner, solidification of the vapor is prevented, and distillate having a temperature higher than the melting point of component B can be obtained. Hot water heated at the condenser 206 is sent to the hot water tank 235 through a line L33. The valve 238 is closed when the temperature of hot water contained in the hot water tank 235 is equal to or higher than a predetermined temperature; and the value 238 is opened when the temperature of hot water contained in the hot water tank 235 is lower than the predetermined temperature.
As mentioned above, the cooling system 225 requires the hot water tank 235 and the cooler 236, among other auxiliary apparatus, resulting in an increase in area occupied by the distillation apparatus as well as an increase in cost.
FIG. 4 is a view for explaining another conventional cooling system. Structural features similar to those in FIG. 3 are denoted by common reference numerals, and repeated description thereof is omitted.
In order to prevent solidification of vapor rich in component B within the condenser 206, cooling oil heated to a temperature higher than the melting point of component B is fed as a cooling medium to the condenser 206.
A cooling system 241 includes an oil tank 242, a cooler 236, a pump 237, and valves 238 and 239. Before operation of the distillation apparatus is started, the valve 238 is opened so as to feed cooling oil heated to a temperature higher than the melting point of component B to the oil tank 242 through a line L32 such that the oil tank 242 stores cooling oil by the hold up volume of the cooling system 241. Cooling oil is sent from the oil tank 242 to the cooler 236 via a line L36, the pump 237, and a line L35. The cooler 236 cools cooling oil to a predetermined temperature higher than the melting point of component B by means of low-temperature water. Thus-temperature-regulated cooling oil is fed to the condenser 206 through a line L34 and causes vapor rich in component B to be condensed within the condenser 206.
In the manner mentioned above, solidification of vapor rich in component B is prevented, and distillate having a temperature higher than the melting point of component B can be obtained. Cooling oil heated at the condenser 206 is sent to the oil tank 242 through a line L33. The valve 238 is closed when the temperature of cooling oil contained in the oil tank 242 is equal to or higher than a predetermined temperature; and the value 238 is opened when the temperature of cooling oil contained in the oil tank 242 is lower than the predetermined temperature.
As mentioned above, the cooling system 241 requires the cooler 236 and the oil tank 242, among other auxiliary apparatus, resulting in an increase in area occupied by the distillation apparatus as well as an increase in cost.
FIG. 5 is a view for explaining still another conventional cooling system.
In FIG. 5, reference numeral 252 denotes a second distillation column, and reference numeral 256 denotes a condenser disposed within the distillation column 252. In order to prevent solidification of vapor rich in component B within the condenser 256, hot water heated to a temperature higher than the melting point of component B is fed as a cooling medium to the condenser 256.
A cooling system 261 includes a hot water tank 262 and valves 263 to 266. For a predetermined period of time after operation of the distillation apparatus is started, the valve 263 is held open to feed steam to the hot water tank 262 through a line L41. In the hot water tank 262, steam and hot water are separated from each other. Hot water heated to a temperature higher than the melting point of component B is fed to the condenser 256 through a line L42 and causes vapor rich in component B to be condensed within the condenser 256. In this manner, solidification of the vapor is prevented, and distillate having a temperature higher than the melting point of component B can be obtained. Hot water (purified water) heated in the condenser 256 becomes pressurized hot water corresponding to the temperature of process steam within the condenser 256. Pressurized hot water is sent to the hot water tank 262 through a line L43. During the abovementioned operation, the valves 264 to 266 are held closed.
When the distillation apparatus enters steady-state operation, pressurized hot water fed to the hot water tank 262 is caused to separate into steam and hot water. Subsequently, the valve 263 is closed, and the valves 264 to 266 are opened. As a result, purified water is fed to the hot water tank 262 through a line L44, and hot water contained in the hot water tank 262 is fed to the condenser 256 through the line L42. Steam contained in the hot water tank 262 is discharged through a line L45 and the valve 265. Hot water contained in the hot water tank 262 is periodically blown out through a line L46 and the valve 266. Through practice of hot-water blow, the interior of the cooling system 261 is cleaned.
As mentioned above, the cooling system 261 requires the hot water tank 262 and the valves 263 to 266, among other auxiliary apparatus, resulting in an increase in area occupied by the distillation apparatus as well as an increase in cost.
FIG. 6 is a view for explaining a conventional vent gas treatment apparatus. Structural features similar to those in FIG. 2 are denoted by common reference numerals, and repeated description thereof is omitted.
A vent gas treatment apparatus 230 employs switching-condenser operation. The condenser 206 is accompanied by two condensers 231 and 232, which are disposed in parallel. One of the two condensers 231 and 232; for example, the condenser 231 is operated, while the other condenser 232 is on standby. Coolant is fed to the operating condenser 231 so as to cool vapor rich in component B mixed with vent gas to a temperature lower than the melting point of component B. The vapor is solidified to become a solid substance rich in component B within the condenser 231.
Solidification mentioned above causes reduction in the heat transfer area of the condenser 231. When the heat transfer area becomes smaller than a predetermined limit, the condenser 231 is brought on standby, and the condenser 232 is started. Compressed air is fed to the condenser 231 to thereby blow out coolant remaining in condenser tubes. Subsequently, steam is fed to the condenser 231 to thereby melt the solid substance rich in component B formed within the condenser 231 into liquid rich in component B. The liquid is discharged through a line L28. Steam is condensed to become condensate, which is discharged from the condenser 231. After the liquid rich in component B is discharged from the condenser 231, coolant is fed to the condenser 231 so as to precool the same.
As mentioned above, the vent gas treatment apparatus 230 requires the condensers 231 and 232, among other auxiliary apparatus, resulting in an increase in area occupied by the distillation apparatus as well as an increase in cost.
FIG. 7 is a view for explaining another conventional vent gas treatment apparatus.
The condenser 206 and a vent gas treatment apparatus 270 are connected by means of a line L71. The vacuum generator 228 and the vent gas treatment apparatus 270 are connected by means of a line L74. The vent gas treatment apparatus 270 employs vent scrubber operation. The vent gas treatment apparatus 270 includes a vent scrubber 271; a pump 273; a heat exchanges 274; and valves 275 and 276. The vent scrubber 271 includes a still section 281 and a packing column section 282.
Solution for adsorbing vent gas and vapor rich in component B is circulated by means of the pump 273. Specifically, the solution discharged from the still section 281 to a line L72 is sent, through a line L73, to the heat exchanger 274 by means of the pump 273. The solution discharged from the heat exchanger 274 is fed to the packing column section 282 through a line L77. The thus-fed solution is sprayed from the top of the packing column section 282 and descends within the packing column section 282. Vent gas is fed to the still section 281 through the line L71 and ascends within the packing column section 282 to thereby be adsorbed by the solution. The solution which has adsorbed vent gas is discharged to the line L72 and is then sent to an unillustrated treatment apparatus through a line L75 at predetermined timing. A line L76 is used to replenish the vent gas treatment apparatus 270 with the solution. The solution has properties capable of sufficiently adsorbing vapor rich in component B having high melting point.
As mentioned above, the vent gas treatment apparatus 270 requires the vent scrubber 271 and the heat exchanger 274, among other auxiliary apparatus, resulting in an increase in area occupied by the distillation apparatus as well as an increase in cost. Furthermore, the solution must has properties capable of sufficiently adsorbing vapor rich in component B having high melting point, thus boosting distillation cost.
A distillation apparatus embodied through modification of the distillation apparatus of FIG. 1 has been provided. The distillation apparatus is configured in the following manner. The top of the first distillation column 201 is connected to the side of the second distillation column 202. In the first distillation column 201, component C is separated from components A and B. In the second distillation column 202, component A and component B are separated from each other to thereby collect component B as a product.
FIG. 8 conceptually shows a conventional distillation apparatus in which a medium-boiling-point component is collected at the bottom of a second distillation column. Structural features similar to those in FIG. 1 are denoted by common reference numerals and repeated description thereof is omitted.
For example, when a material liquid M containing three components A, B, and C is fed into the third section 213 of the first distillation column 201, vapor rich in components A and B is discharged from the top of the first distillation column 201 and sent to the condenser 204, where the vapor is condensed into liquid rich in components A and B. The liquid rich in components A and B is discharged as distillate from the condenser 204. A portion of the distillate is refluxed into the first distillation column 201, whereas the remaining distillate is fed into the third section 218 of the second distillation column 202.
Liquid rich in component C is discharged as a column-bottom liquid from the bottom of the first distillation column 201. A portion of the column-bottom liquid is sent to the evaporator 203, where the column-bottom liquid is evaporated through application of heat to become vapor rich in component C. The vapor rich in component C is returned to the first distillation column 201. The remaining column-bottom liquid is discharged to an external destination.
When the distillate is fed into the third section 218, vapor rich in component A is discharged from the top of the second distillation column 202 and sent to the condenser 206, where the vapor is condensed into liquid rich in component A. The liquid rich in component A is discharged as distillate from the condenser 206. A portion of the distillate is refluxed into the second distillation column 202, whereas the remaining distillate is discharged to an external destination.
Liquid rich in component B is discharged as a column-bottom liquid from the bottom of the second distillation column 202. A portion of the column-bottom liquid is sent to the evaporator 205, where the column-bottom liquid is evaporated through application of heat to become vapor rich in component B. The vapor rich in component B is returned to the second distillation column 202. The remaining column-bottom liquid is discharged to an external destination.
When separation of component C is insufficient in the first distillation column 201, component C gathers as an impurity in the vicinity of the bottom of the second distillation column 202. When components B and C are heated in the evaporators 203 and 205, respectively, components B and C are decomposed to form modified components Bxe2x80x2 and Cxe2x80x2 having a high boiling point. Thus, modified components Bxe2x80x2 and Cxe2x80x2 also gather as impurities in the vicinity of the bottom of the second distillation column 202. As a result, component B collected as a product contains impurities, such as component C and modified components Bxe2x80x2 and Cxe2x80x2.
Component C and modified components Bxe2x80x2 and Cxe2x80x2 have large molecular mass of carbon and thus affect hue and odor of the product.
Since the product is collected at the bottom of the second distillation column 202, the product is exposed to high temperature induced by the evaporator 205 disposed at the column bottom. As a result, component B, which is a product, is decomposed to form modified component Bxe2x80x2 having a high boiling point, with a resultant impairment in product quality.
In order to cope with the above problem, there is provided a distillation apparatus which collects a product in the form of vapor, not in the form of liquid.
FIG. 9 conceptually shows a conventional distillation apparatus which collects a product in the form of vapor. Structural features similar to those in FIG. 8 are denoted by common reference numerals, and repeated description thereof is omitted.
A second distillation column 202 includes, from top to bottom, a first section 216, a second section 217, a third section 218, a fourth section 219, a fifth section 331, a sixth section 332, and a seventh section 333. A packing element is disposed in each of the second section 217 and the fourth section 219, to thereby form an enriching section in the second section 217 and an exhaust section in the fourth section 219. A demister is disposed in the sixth section 332.
Vapor rich in component B is collected as a product from the fifth section 331 and fed to a condenser 336 via a valve 335. In the condenser 336, the vapor is condensed into liquid rich in component B. The liquid rich in component B is discharged from the condenser 336 as a column-bottom liquid. The liquid is fed to a receiver 337 and accumulated therein. The liquid is then discharged from the receiver 337.
In order to carry out distillation in a low-temperature region for prevention of impairment in product quality and to reduce energy consumed for heating a portion of a column-bottom liquid in evaporators 203 and 205, a vacuum generator 338 is disposed for use with the condensers 204 and 206, and a vacuum generator 339 is disposed for use with the condenser 336. The vacuum generators 338 and 339 generate a negative pressure within the first and second distillation columns 201 and 202. Thus, the column-bottom liquids can be readily evaporated. Also, vent gas generated within the first and second distillation columns 201 and 202 can be drawn out and released into the atmosphere.
Even though impurities gather in the vicinity of the bottom of the second distillation column 202, vapor rich in component B is not collected from the bottom of the second distillation column 202, but is collected as a product from the fifth section 331. Thus, the product does not contain impurities; therefore, the hue and odor of the product are not affected. The product is collected from the fifth section 331; i.e., the product is not exposed to high temperature induced by the evaporator 205 disposed at the column bottom, thereby enhancing product quality. Impurities gathering in the vicinity of the bottom of the second distillation column 202 are discharged through a line L240.
There has been provided a distillation apparatus in which a product is collected in the form of liquid, and impurities are removed from the product.
FIG. 10 conceptually shows a conventional distillation apparatus in which impurities are removed from a product. Structural features similar to those in FIGS. 8 and 9 are denoted by common reference numerals, and repeated description thereof is omitted.
Liquid rich in component B is collected from the fifth section 220 as a column-bottom liquid and as a product and fed to a receiver 342 via a valve 341. The receiver 342 and a heater 344 are connected. The product fed to the receiver 342 is then fed to the heater 344, where the product is evaporated to become vapor rich in component B. In the heater 344, the vapor rich in component B is separated from impurities, such as component C and modified components Bxe2x80x2 and Cxe2x80x2. The vapor rich in component B, which is free of impurities, is returned to the receiver 342.
Subsequently, the vapor rich in component B is fed to a condenser 343 for use with a product. In the condenser 343, the vapor is condensed into liquid rich in component B. The liquid rich in component B is discharged from the condenser 343. The liquid is fed to a receiver 345 and accumulated therein. Then, the liquid is discharged from the receiver 345 and sent to an external destination via a valve 346. In the course of operation mentioned above, impurities are accumulated within the receiver 342. Thus, when the operation is performed for a predetermined period of time, the impurities are removed through a line L248. Reference numeral 347 denotes a vacuum generator.
The above-mentioned conventional distillation apparatus adapted to collect a product in the form of vapor requires the valve 335, the condenser 336, and the receiver 337, among other auxiliary apparatus. The above-mentioned conventional distillation apparatus adapted to collect a product in the form of liquid and adapted to remove impurities from the product requires the valves 341 and 346, the receivers 342 and 345, the condenser 343, and the heater 344, among other auxiliary apparatus. Thus, the size and cost of the distillation apparatus increase.
Also, the distillation apparatus require complicated equipment for controlling and maintaining the same. In particular, in the case of the distillation apparatus adapted to collect a product in the form of vapor, the flow rate of vapor discharged from the fifth section 331 must be regulated by means of the valve 335. However, since control of vapor is very complicated, involvement of vapor control pushes up the cost of the distillation apparatus.
An object of the present invention is to solve the abovementioned problems in the conventional distillation apparatus and to provide a distillation apparatus which allows a reduction in area occupied thereby and which can be manufactured and operated at low cost, as well as to provide a distillation method employing the distillation apparatus.
Another object of the present invention is to provide a distillation apparatus enabling removal of impurities from a product to thereby prevent adverse effect on hue and odor of the product which would otherwise result from the impurities, as well as to provide a distillation method employing the distillation apparatus.
To achieve the above objects, the present invention provides a distillation apparatus comprising a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section, to which a material liquid is fed through a feed nozzle and which is formed above the feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; a third distillation section having an enriching section connected to and formed above a lower end of the first distillation section, and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition, and an exhaust section formed below the lower end; a condenser connected to the top of the column body and adapted to condense vapor rich in a low-boiling-point component discharged at the top; negative-pressure generation means connected to the condenser and adapted to generate a negative pressure to thereby withdraw vent gas from the column body; a gas cooler for cooling the vent gas disposed between the condenser and the negative-pressure generation means; a first discharge system disposed at the side of the column body and adapted to discharge liquid rich in a medium-boiling-point component formed from a high-melting-point material; and a second discharge system disposed at the bottom of the column body and adapted to discharge liquid rich in a high-boiling-point component formed from a high-melting-point material.
The first discharge system has first solidification prevention means for preventing solidification of the liquid rich in the medium-boiling-point component. The second discharge system has second solidification prevention means for preventing solidification of the liquid rich in the high-boiling-point component.
In this case, the vapor rich in the low-boiling-point component is discharged at the top of the column body, and the low-boiling-point component is formed from a low-melting-point material. Thus, there is no need to employ various auxiliary apparatus such as a hot water tank, a cooler, an oil tank, a condenser, and a vent scrubber.
Thus, the distillation apparatus allows a reduction in area occupied thereby and can be manufactured and operated at low cost.
Preferably, the first and second solidification prevention means each assume a double-pipe structure comprising an inner pipe and an outer pipe disposed concentrically and in which a heating medium is caused to flow through the space between the inner and outer pipes to thereby prevent solidification of the liquid flowing through the inner pipe.
Further preferably, the first and second solidification prevention means are each steam tracing comprising a primary pipe and a secondary pipe disposed in parallel and in which a heating medium is caused to flow through the secondary pipe to thereby prevent solidification of the liquid flowing through the primary pipe.
The present invention provides another distillation apparatus comprising a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section, to which a material liquid containing a low-boiling-point component, a medium-boiling-point component, and a high-boiling-point component is fed through a feed nozzle and which is formed above the feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; a third distillation section having an enriching section connected to and formed above a lower end of the first distillation section, and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition, and an exhaust section formed below the lower end; a condenser connected to the top of the column body and adapted to condense vapor rich in a low-boiling-point component discharged at the top; a side cut nozzle disposed at the side of the column body and adapted to discharge liquid rich in the medium-boiling-point component as a product at the side; an evaporator disposed at the bottom of the column body and adapted to generate vapor through application of heat to liquid rich in a high-boiling-point component discharged at the bottom; and a cooler connected to the side cut nozzle and adapted to cool the product.
In this case, the liquid rich in the medium-boiling-point component is enriched in the exhaust section of the second distillation section and discharged as a product at the side of the column body. The liquid rich in the high-boiling-point component is enriched in the exhaust section of the first distillation section and in the enriching section of the third distillation section. The thus-enriched liquid rich in the high-boiling-point component is further enriched in the exhaust section of the third distillation section and is then discharged at the bottom of the column body. A modified component formed through decomposition of the medium-boiling-point component is collected in the vicinity of the bottom of the column body and is then discharged at the column bottom.
Accordingly, the medium-boiling-point component does not contact the high-boiling-point component and the modified component while these components are in the form of liquid. Thus, the medium-boiling-point component collected as a product does not contain the high-boiling-point component and the modified component, which are impurities. As a result, the hue and odor of the product are not affected.
Also, entry of impurities into a product can be prevented without use of auxiliary apparatus such as a valve, a product condenser, a receiver, and a heater, thereby reducing the size of the distillation apparatus and the cost of manufacture and operation of the distillation apparatus. Furthermore, there can be simplified equipment for controlling the operation of the distillation apparatus and maintaining the distillation apparatus. Since a product can be collected in the form of liquid, flow rate control of the product can be significantly simplified, thereby reducing the cost of manufacture and operation of the distillation apparatus.
Since a product is collected at the side of the column body, the product is not exposed to high temperature induced by the evaporator disposed at the bottom of the column body. Also, the product does not require additional heating by a heater. Thus, formation of a modified component within the product can be prevented, thereby enhancing product quality.
The product collected at the side of the column body is immediately cooled by the cooler, thereby preventing decomposition of the medium-boiling-point component which would otherwise result from heat held by the product itself. Formation of a modified component within the product can be prevented more reliably.
The present invention provides a further distillation apparatus comprising: a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section, to which an adjusted material liquid comprising a material liquid and an additive component is fed through a feed nozzle and which is formed above the feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; a third distillation section having an enriching section connected to and formed above a lower end of the first distillation sections and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition: and an exhaust section formed below the lower end; a condenser disposed at the top of the column body and adapted to condense vapor rich in the additive component into liquid rich in the additive component and to discharge the liquid rich in the additive component as distillate; a first discharge system disposed at the side of the column body and adapted to discharge liquid rich in a low-boiling-point component formed from a high-melting-point material; and a second discharge system disposed at the bottom of the column body and adapted to discharge liquid rich in a high-boiling-point component.
The boiling point of the additive component is lower than that of the low-boiling-point component.
In this case, the adjusted material liquid is obtained through addition, to a material liquid, of an additive component lower in boiling point than the low-boiling-point component. The adjusted material liquid is fed to the first distillation section through the feed nozzle. Thus, vapor rich in the additive component is discharged from the top of the column body. There is no need to collect the low-boiling-point component as a product at the top of the column body. Vapor rich in the additive component is condensed by means of the condenser; i.e., there is no need to condense vapor rich in the low-boiling-point component by means of the condenser.
Thus, there is no need to employ various auxiliary apparatus such as a hot water tank, a cooler, an oil tank, a condenser, a vent scrubber, and a heat exchanger, thereby reducing the size of the distillation apparatus and the cost of manufacture and operation of the distillation apparatus.
Preferably, a portion of the distillate is refluxed into the column body, and the remaining distillate is added as an additive component to the material liquid.
In this case, the additive component can be repeatedly used through addition to the material liquid, thereby reducing the cost of operation of the distillation apparatus.
Further preferably, a portion of the distillate is refluxed into the column body; the remaining distillate is discharged; and an additive component is added for, replenishment in an amount corresponding to the amount of the distillate to be discharged.
Still further preferably, all of the distillate is refluxed into the column body; and in order to start operation of the distillation apparatus, an additive component is added in a predetermined amount to the material liquid.
Still further preferably: the distillation apparatus further comprises negative-pressure generation means connected to the condenser and adapted to generate a negative pressure to thereby withdraw vent gas from the column body; and a gas cooler for cooling the vent gas disposed between the condenser and the negative-pressure generation means.
Still further preferably, the first discharge system has solidification prevention means for preventing solidification of the liquid rich in the low-boiling-point component.
The present invention provides a distillation method applicable to a distillation apparatus comprising a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section formed above a feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; and a third distillation section having an enriching section connected to and formed above a lower end of the first distillation section, and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition, and an exhaust section formed below the lower end.
The distillation method comprises the steps of feeding an adjusted material liquid comprising a material liquid and an additive component to the first distillation section through the feed nozzle; condensing vapor rich in the additive component into liquid rich in the additive component at the top of the column body; discharging the liquid rich in the additive component as distillate; discharging liquid rich in a low-boiling-point component formed from a high-melting-point material at the side of the column body; and discharging liquid rich in a high-boiling-point component at the bottom of the column body.
The boiling point of the additive component is lower than that of the low-boiling-point component.
The present invention provides a further distillation apparatus comprising a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section, to which an adjusted material liquid comprising a material liquid and an additive component is fed through a feed nozzle and which is formed above the feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; a third distillation section having an enriching section connected to and formed above a lower end of the first distillation section, and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition, and an exhaust section formed below the lower end; a condenser disposed at the top of the column body and adapted to condense vapor rich in a low-boiling-point component into liquid rich in the low-boiling-point component and to discharge the liquid rich in the low-boiling-point; a first discharge system disposed at the side of the column body and adapted to discharge liquid rich in a high-boiling-point component; a second discharge system disposed at the bottom of the column body and adapted to discharge liquid rich in the additive component as a column-bottom liquid; and an evaporator for evaporating the column-bottom liquid to thereby obtain vapor rich in the additive component.
The boiling point of the additive component is higher than that of the high-boiling-point component.
In this case, since a modified component formed through decomposition of the high-boiling point component gathers in the vicinity of the bottom of the column body, the modified component and the high-boiling-point component do not contact each other while these components are in the form of liquid. Thus, the product to be collected does not contain the modified component, which is an impurity. As a result, the hue and odor of the product are not affected.
Also, entry of impurities into a product can be prevented without use of auxiliary apparatus such as a valve, a product condenser, a receiver and a heater, thereby reducing the size of the distillation apparatus and the cost of manufacture and operation of the distillation apparatus. Furthermore, there can be simplified equipment for controlling the operation of the distillation apparatus and maintaining the distillation apparatus. Since a product can be collected in the form of liquid, flow rate control of the product can be significantly simplified, thereby reducing the cost of manufacture and operation of the distillation apparatus.
Since a product is collected at the side of the column body, the product is not exposed to high temperature induced by the evaporator disposed in the vicinity of the bottom of the column body. Also, the product does not require additional heating by a heater. Thus, formation of a modified component, which becomes an impurity, within the product can be prevented, thereby enhancing product quality.
Preferably, a portion of the column-bottom liquid is fed to the evaporator; and the remaining column-bottom liquid is added as an additive component to the material liquid.
In this case, the additive component can be repeatedly used through addition to the material liquid, thereby reducing the cost of operation of the distillation apparatus.
Further preferably, most of the column-bottom liquid is fed to the evaporator; the remaining column-bottom liquid is discharged; and an additive component is added for replenishment in an amount corresponding to the amount of the column-bottom liquid to be discharged.
Still further preferably, all of the column-bottom liquid is fed to the evaporator; and in order to start operation of the distillation apparatus, an additive component is added in a predetermined amount to the material liquid.
Still further preferably, the first discharge system has cooling means for cooling the liquid rich in the high-boiling-point component.
In this case, the product collected at the side of the column body is immediately cooled by the cooling means, thereby preventing decomposition of the high-boiling-point component which would otherwise result from heat held by the product itself. Formation of a modified component within the product can be prevented.
The present invention provides another distillation method applicable to a distillation apparatus comprising a column body; a partition for dividing the interior of the column body into a first chamber and a second chamber, which are adjacent to each other; a first distillation section having an enriching section formed above a feed nozzle, and an exhaust section formed under the feed nozzle; a second distillation section having an enriching section connected to and formed above an upper end of the first distillation section, and an exhaust section formed below the upper end and located adjacent to the enriching section of the first distillation section while being separated from the same by the partition; and a third distillation section having an enriching section connected to and formed above a lower end of the first distillation section, and located adjacent to the exhaust section of the first distillation section while being separated from the same by the partition, and an exhaust section formed below the lower end.
The distillation method comprises the steps of feeding an adjusted material liquid comprising a material liquid and an additive component to the first distillation section through the feed nozzle; condensing vapor rich in a low-boiling-point component into liquid rich in the low-boiling-point component at the top of the column body; discharging the liquid rich in the low-boiling-point component at the top of the column body; discharging liquid rich in a high-boiling-point component at the side of the column body; discharging liquid rich in the additive component as a column-bottom liquid at the bottom of the column body; and evaporating the column-bottom liquid to thereby obtain vapor rich in the additive component.
The boiling point of the additive component is higher than that of the high-boiling-point component.